CVE-2023-25571: backstage Cross-site Scripting

Vulnerability summary

CVE-2023-25571 is a medium (CVSS 6.8) Cross-site Scripting vulnerability in backstage. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.9% of scored vulnerabilities.

Timeline

1. 14-02-2023
   PublishedVulnerability first disclosed.
2. 10-03-2025
   Last modifiedVulnerability information updated.

Description

Backstage is an open platform for building developer portals. `@backstage/catalog-model` prior to version 1.2.0, `@backstage/core-components` prior to 0.12.4, and `@backstage/plugin-catalog-backend` prior to 1.7.2 are affected by a cross-site scripting vulnerability. This vulnerability allows a malicious actor with access to add or modify content in an instance of the Backstage software catalog to inject script URLs in the entities stored in the catalog. If users of the catalog then click on said URLs, that can lead to an XSS attack. This vulnerability has been patched in both the frontend and backend implementations. The default `Link` component from `@backstage/core-components` version 1.2.0 and greater will now reject `javascript:` URLs, and there is a global override of `window.open` to do the same. In addition, the catalog model v0.12.4 and greater as well as the catalog backend v1.7.2 and greater now has additional validation built in that prevents `javascript:` URLs in known annotations. As a workaround, the general practice of limiting access to modifying catalog content and requiring code reviews greatly help mitigate this vulnerability.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
• CWE-84Improper Neutralization of Encoded URI Schemes in a Web PageThe web application improperly neutralizes user-controlled input for executable script disguised with URI encodings.